1. Field of the Invention
The present invention relates to control logic for controlling upshifting in an at least partially automated mechanical transmission system having a device for providing a controllable retarding torque to the transmission input shaft and associated jaw clutch members and gearing to retard rotation thereof in a controllable manner.
2. Description of the Prior Art
The requirement of decreasing the rotational speed of the input shaft and the gears, jaw clutch members and shafts rotating therewith to accomplish an upshift in a mechanical transmission is well known in the prior art. Fully and partially automated vehicular mechanical transmission systems utilizing automatically controlled input shaft rotation retarding devices, such as engine brakes and/or input shaft brakes, to achieve smooth and/or rapid upshifts are known in the prior art, as may be seen by reference to U.S. Pat. Nos. 4,361,060; 4,595,986; 4,614,126; 4,648,290; 4,676,115; 5,425,689; 5,436,833; 5,409,432 and 5,582,558, the disclosures of which are incorporated herein by reference. Input shaft brakes, also called inertia brakes and upshift brakes, which apply a direct or indirect frictional or fluidic retarding force to the input shaft, are known in the prior art, as may be seen by reference to U.S. Pat. Nos. 5,086,659 and 5,528,950 and allowed application Ser. No. 08/681,255 (assigned to the assignee of this application), the disclosures of which are incorporated herein by reference.
The prior art controls for fully or partially automated vehicular mechanical transmission systems having controllable input shaft retarding devices have not optimized upshifting by controlling the retarding devices to retard input shaft rotation as a predetermined function of sensed previously engaged or target gear ratio and/or operator throttle pedal setting.